Forgotten Realms: Condemnation (War of the Spider Queen #3) by Richard Baker

The War of the Spider Queen explodes!

From the burning sands of Anauroch to the limitless labyrinth of the Underdark, an epic quest for the very essence of the Spider Queen takes one startling turn after another. Powerful forces are at work to find answers to where Lolth has gone. She may return as something greater than she was, or she may have gone from her drow children forever, leaving them to their own devices in a chilling Condemnation...